Composite products comprising a reinforcing woven material and a PTFE foil are used for many different industrial purposes. Within the chemical industry, this kind of material is, for example, used for vessels, compensators, containers, conveyor belts and chemical barriers. Such objects must be able to resist strong chemical and thermal impacts. This is also a consideration within power plants, the food industry and many other applications where reliable and strong mechanical and/or chemical properties are also important.
In a composite material, like those discussed above, interactions between materials in the composite will create the properties that make the composite material suitable for a given application. Typically, the woven material will improve the mechanical properties during a thermal impact whilst the applied PTFE foil or foils will provide barrier properties that may be maintained even under high temperatures. 
However, it has proven difficult to obtain a proper “balance” between the individual components of the composite material during its manufacture. This is because a composite product typically shrinks during the manufacturing, so that the final composite product displays significantly different dimensions than those of the original laminated product. This can be a particular problem in the manufacture of composite products with pre-determined final dimensions, because there is a tendency for the composite product, especially the edge regions, to bend or wrinkle.
Apart from the problem of the composite shrinking or otherwise becoming disfigured, it can also be difficult to predict the dimensions of the final product. This can make further machining after lamination necessary. Further machining is often not possible to automate and can result in material waste.
A composite product such as the above can shrink up top 10%. In such a situation, the amount of material wasted can be a significant factor in the final production price of such composites.
One way of improving the manufacturing process is by adding an extra layer of coating during lamination of the woven material and the PTFE coils. This solution however makes the manufacturing process more expensive, results in an increased use of material, and results in a finished composite material with an increased thickness and weight. 